Swimming pool



FIG. 1 is a perspective view, looking from above, of a swimming pool showing my new design;

FIG. 2 is a right side elevational view thereof, the left side elevational view being substantially identical;

FIG. 3 is a top plan view thereof; and

FIG. 4 is a bottom plan view thereof. 

The ornamental design for a swimming pool, as shown and described. 